Originally Posted by bostontrevor
http://www.bikeforums.net/showthread.php?t=52599
Shaft drive doesn't really solve any problems that aren't solved by a full chaincase, it's an idea whose time has never come. It's more than a century old but every few decades someone rediscovers it and thinks they've really got something.
I've ridden a Dynamic and it felt like a bike. The drivetrain felt remarkably smooth but nothing magical.
Internally geared hubs are almost as old. Unlike shaft drive, they have some real utility. They're not as efficient or as light as a derailleur system but they are virtually maintenance free, well suited to messy conditions, very durable, and can be shifted even when not moving.
I'm thinking it might solve the problem of all my right pant legs getting greasy on my commute. I'm already running a nexus 7 rear hub, dynamo front hub, and carrying a 20+ lb backpack, so a little more load won't hurt much. Long term trial would be needed to see if maintenance were easier. "Just shoot grease in through the nipples regularly" they told me when I test rode one. It felt no different than a chain drive.
..Or maybe a chain guard would accomplish the same thing.